Thermostat.



E. W. COMFORT.

THERMOSTAT.

APPLICATION FILED JULY 30,1903.

Patented Feb. 16, 1909i.

2 SHEETS-SHEET 1.

Troma/F E. W. COMFORT.

THERMOSTAT. APPLIOATION TTLTD JULY 30,1903.

Patented Feb. 16, 1909 2 SHEETS-SHEET 2 Arrow/VE r.

EDWARD W. COMFORT, OF CHICAGO, ILLINOIS, ASSIGIOR lO XATIONL REGU-LWIOR COM- PANY, OF CHICAGO, ILLINOIS, A CORPORATION OI? ILLIrYOIS.

THERMOSTAT.

Specification of Letters Patent.

Pei-@amenait ie, ieee".

Application filed. July 30, 1903. Serial No. 167,545.

Which the following is a full, clear, concise,A

and exact description, reference being had to the accompanying drawing, forming a part of this specification.

My invention relates toapparatus for a-utoinatically controlling the temperature in buildings and other places.

of such apparatus in which the heating and ventilationl ot the apartment are ettected through the medium mixture of hot and cold air, dampers are generally arranged in the passages or ducts tor the hot and cold 4air.

These dampers are operated by a fluid pressure motor to vary the respectivo quantitles ot hot and cold air admitted to the apartment.' The motor is supplied with tluid under pressure from a suitable source and a tliermostatic element arranged vvithin the apartment controls av valve which regulates the flow ot fluid under pressure admitted to the niotoi'.. The best results in controlling the temperature and producing proper ventilation of the. apartment are attained by gradually varying the relative quantities of liot'and cold air admitted, as ,suddenly changing the, proportions of the mixture of hot and coldI air. or admitting only one or the other at a time, produces too rapid a change in the temperature and does not etiect uniform regulation. YIt is therefore sought to have the motor gradually change the position of the dampers under variations of the temperature in the apartment, but the usual form ot' motor employed will not gradually change the position ol" the dampers unless tlieaction of the tlicrniostatic clement upon the valve which regulates the pressure supplied to the motor, is modied. One torni ot thermostat tor regulatingr -the pressure supplied to' 'the motor, so as to produce a gradual change, in the position of the dampers, I have dosc'iiibed and claimed in Patent No. S3726() issued to ine November 2T. 15H0. In tha" patent I have shown a thermostat in which the pressure supplied to the motor acts upon a Bourdon' tube to produce a i'uovement ot the valve independcnt ot' that eil'ectcd by the tlierinic action.

In that classa It is the design of the present invention to simplify the construction and reduce the cost of manufacture ot a thermostat which ivillicgulate the pr saure supplied tothe motor in such a manner as to cause the motor to produce a gradual change in the position of the dempers Which control the admission of hot and cold air to the apartment.

I construct rmy thermostat, in its preferred :toi-in, Witli"a valve actuated by a` thermostatic element and inelosed Within a suitable casing, and with `means which permits an action of said valve independent of that produced by said thermostatie element and dependent upon the relative pressures vvithn inthe inclosing easing and the tiuid supply pipe. i

.ln or the purpose of revealing my invention. I have, in the accompanying` drawings, illustrated two forni thereof, but as my invention may be embodied in many construc-` tions. I do not desire to limit inyscliE to any specific device. except as is particularly set 'out in the claims.

support; Fig. 5 is an elevation of the-upper l partv ot the valve support; Fig. G isa side vien' of the part shown in Fig. 5; Fig. 7 is a sectional elevation of a modification ot" the preferred embodiment of my invention; 8 is a partial sectional view of the lower portion of the device shown in Fie'. 7, and Fig. Si is a diagraimuatic viciv showing one form oi' my improved apparatus arranged for controlling` the temperature and ventilation of an apartment.

.lln'oughoutA the accompanying drawings, like reference characters designate simil-ar and corresponding parts.' Referring first to Fig. 9, in a iooni l 'to be heated isai'ranged my improved thermostat 2. which is connected by a pipe t with a tank containing fluid under piessure. and by another pipe (l, with a motor T. vThe dam pers 8 and E) are operated-by the motor to vrrv the relative quantities ot' hot and cold air supplied to the room through a register l0, the damper 8 being arranged to regulate IUS iio

- the lower end of a pin or rod 26, and upon SUI'G.

ranged to regulate the quantity of hot air l through the pipe G. In other words, the

delivered from the hot air chamber 12, in which the airis heated, preferably by a steam coil 13; Y

ferred form of vimproved thermostat is illustrated in Figs. 1 to 6 inclusive of the drawings. The thermostat has a tube or chamber 14 of hard rubber or any other material highly responsive to temperature changes. a

The lower end of the tube preferably has screwed thereinto a plug 15 from which a post 16 projects into the tube.v Extending from the upper end of said post is a prefer- `ably flat spring 17 which supports a bloek 18, having depending therefrom a preferably Hat spring 19 which carries a valve arm 20, the lower end of which constitutes a valve. The seat 21 for the valve has a port or passage 22 extending to the pipe 4 connected with the plug 15, there being provided in said port or passage a filter 23.. The spring 17 is so set as to tend to normally hold the valve away from the seat, as illustrated, while the c:set of the spring 19 is such that it tends to move the valve toward its seat against the flow of fluid therefrom. The pipe 4, as' before explained, leads to the tank containing fluid under pressure, or any other suitable source of'supply of Huid under pres- The other pipe 6, leading to the motor, is also connected with the plug 15 and communicates with a port 24 which extends through said plug and opens into the chamber within the tube 14, said pipe being pro- `vided -witha -vent 25 of somewhat less dimensions than the passage in said pipe and the port 24. Upon the top of the block 18 bears the upper end of said pin bears the point of a screw 27 which passes through a plug 28, preferably threadedV into the upper end of the tube 14. In assembling the parts of the thermostat, the pin or rod 26, after being set upon the block, is held in a central position by the disk or plate 30, which engages the inner walls of the tube, until the screw is brought to bear upon the top of lsaid pin. By turning the screw the position of the valve relative to its seat may be adjusted. After the screw has been set, it is preferably covered with a cap or casing 29 threalded upon the plug 28, to give the thermostat a finished appearance, and to protect the screw.

In the operation of the apparatus the tube or thermostatie element 14 will expand and contract under rise and fall of the temperature, and in so doing it will move the block 18, by bending the spring 17, through the agencydof the pin 26, thus varying the pressure eterted by the spring 19 upon the valve 20, and consequently varying the quantity of air permitted to escapefrom the tank through the port 22 and to pass from the chamber of the .thermestat to the motor energy which is stored in the spring 19, and which tends to close the valve against the l flow of fluid into the chamber, is varied to The particular construction of my pre 2 correspond to changes in the temperature of the room.` lf air is allowed to pass the valve from the tank to the motor for a su'l'licicnt i length of time the pressure in the motor will become the saine as the pressure in the tank, and, consequently, the pressures upon both sides of the valve will be equal. That is to say, the pressure in the chamber of the thermostat, or on the motor side of the valve,

y will be equal to that in the tank, or on the supply side of the valve. lVith the full pressure present in the motor the dampers will be moved into, and held in, such a posi tion that the quantity of cold air supplied to the room will be greatly increased, while the quantity of bot air will be decreased. This will result in the lowering ofthe temperature of. the room, which will cause the thermostatic element 14 to contract and depress the block 18, increasing the tendency of the spring 19 to close the valve upon the port leading from the tank and shut off theY air supply. v

Referring to the pressure from lthe tank as the supply pressure and to the pressure in the closed chamber, that is, the motor pressure, as the back pressure, it will be noted that the eeetive pressure tending to open the valve will -be equal to the supply pressure less the back pressure. The tendency of the valve to open, due to the effective pressure, is opposed by the spring 19, which will be termed the balancing or energy storage spring, to distinguish it from the supporting spring 17. The supply pressure is practicall constant, but the back pressure would gracliially fall if the valve remained closed, this being due to the escape of fluid through the vent 25. To compensate for this the valve must remain slightly open, or must open and close in rapid succession. The regulation results from the balancing and unbalancing action of the two opposing forces, that is, the effective pressure and the power of the energpstoringspring, to which the valve is subjected Y For the purpose of illustration ietv it be assumed that the temperature of the apartment in which the thermostat is placed is to be kept at F. At this temperature the thermostatic tube will. sassume a. definite length, and for this length of the tube the parts will assume such a position that the. valve, by remaining slightly open or by re-1 peatedly opening and closing in rapid succession. will permit the passage of fluid to ,fthe closed chamber, and to the motor. at such a rate as to maintaintherein a definite pressure, notwithstanding the constant leakage through the vent port 25. The ell'ective fluid pressure and the spring pressure are til) 'static tube will expand accordingly, thereby new nicely balanced, the valve opening more or less as the/,one or thc other predominates, and maintaining a practically constant pressure in the pipe leading to the motor, thus holding the valve or damper controlled by the motor in a delinite position so long as the temperature in the room remains at the de sired point of 70 l?. Assuming, now, that the temperature rises to 71o; the thermorelieving somewhat the pressure on the block J and decreasing the pressure exerted by the spring 19. Since the effective iuid pressore is now greater than the opposing force oi the power storage spring 19 the valve is moved away' trom its seat by the luidto admit more Huid to the chamber, thus 1n` creasing the bach pressure by permitting fluid tolow in faster than it can escape through the vent 25. `As the back Apressure rises, the flow of uid into the chamber through the valve port is opposed more and more, until at' length the eil'ective pressure, or the pressure at the port, is reduced to such an extentI that it is again balanced by the pressure of lthe spring. The pressure in the chamber and motor is noW maintained constant but higher than before, the escape of fluid through the vent port beingv greater than before, but being compensated 'for by the increased tloiv of fluid into the chamber through the valve port. The increased back pressure has caused the motor diaphragm to move to a new position, moving with it the heat damper or valve to a position wherein less heat is supplied to the room` and holds the same at this position until the temperature has fallen to the ded TOO. it the temperature falls below thc assumed desired point of o, the Athermostatic tube, by contracting, increases the power stored in the springy 19, which soon begins to dominate the effect-ive pressure and move the valve toward the inlet port, thereby permitting` the back pressure to fall, due to the escape of `fluid through the vent port `25 faster than it enters at the valve port. The rf uitingr increase in the effective pressure soon causes the latter to again balance the power oi' the spring' 19, When the back pres-- sure wwill be maintained constant to hold the lured damper or valve in a nciv position soY r; as the temperature remains at 69. bark or motor prt sure is now lower :uan when the temperature Was at 700, and tl clore, the escupe ot fluid through the vont port is less rapid` being, however, 2. wily. tum'ipensated tor by 'the decreased :"orv ot duid through the valve port. ii/'tseu 'the thermostatic element tends to move the valve to close the port, the movement ot the valve will be slovccr as the etl'ective pressure niet port becomespleister, and conmuthe ihcrnristatie eien'icnt per 'to move in the opposite direction, the openinpr of the' valve. will be slower as the ell'ectivo 'pressure becomes less. For this` reason the movement. of the valve under the action of the thermostatic element is uniterially retarded or modified so that the pressure at the motor is varied in such a manner as to cause-the positions of the dampers to be gradually changed, When variation inthe temperature in the apart-ment takes place. Under ordinary conditions the movement of the dampers is hardly perceptible, since such uniform regulation results from use of this thermostatthat the expansion and contraction 'of the tube or thermos-tatie element is very slight.

The above. analysis or' theoperation of my device makes it plain that the heat respon-A sive elementserves to vary the tension of the balancing spring1 19 and that, therefore. the buck pressure is automatically'readjusted until the etlective fluid pressure reaches a condition of equilibrium with respect tol the spring pressure. The movement of the fluid supply valve is-thus modified and instead of following the precise movement of the therniosta'tic element, partalres of a retarded movement, due to the-tension of the balancing spring, which prevents the valve from moving 1n a direction toopen or to close the port as rapidly as would 'be the case vvere the valve `connected directly and unyieldingly to the thermostatic element.

The back pressure or motor pressure never acts in opposition to the thermostatic pressure, butin unison with it and supplementary thereto, thusI when the thermostatic tube contracts, tending to close the valve 21, the back pressure act-s in unison, also tendingI to close the valve.

l t will be seen that Whereas in the device of Patent No. 837,260, heretofore mentioned, l have provided means in the form of'a Bourdon tube to respond to the motor or back. pressure to n'iodii'y the movement of the fluid supply valve, I yhave entirely eliminated such means in the present structure, and by balancing the e'llective fluid pressure against a spring; Whose tension is automatically varied by the thermostatic element, l accomplish Va'guadual movement ofi the heat damper or valve and maintain the heut dam per or valve absolutely fixed. in position so lonfrv as the temperature remains constant. Moreover, ll retain the advantageous features of my above mentioned prior device, wherein the thermostatic element is persni't-d to move -unini'peded tlnoughout its entire range otq travel when the temperature changes, the movcuient ot the fluid supply the movement of the thermostatic element itself.

ln Fig'. T is illustrated another form ofi thermostat. embodying my iinprovenients. Instead of tho valve arm beingflexibly connected with the block 18as in the, other construction. it is rigidly connected therewith, and the 'retardation of t-he movement of said valve under the thermie action by variation in the pressure upon the valve of vthe tluid in the supply pipe due to the variation ir the pressure of' the fluid in the thermostatic tube is permitted by the, coil spring lll which makes the pin ")6 yieldingly press upon the block 18.

lt is obvious that my invention may be embodied in many mechanisms, and that the devices shown herein for, the purpose of disclosing,r my invention. are susceptible of many changes, and, therefore, I do not wish to be limited in my invention except as I particularly specify in the appended claims, and where in the said claims I have referred to a valve l I contemplate not only a single valve, but any valve combination or valve mechanism capable of accomplishing substantially similar results. Furthermore, my improved thermostat may be arranged in any system of apparatus for controlling teniperatu'res wherein its use will produ ,e advantageous results, and by a` different arrangement of the valve and the ports leading into the interior of the valve chamber, the changes in pressure on opposite; ides of the valve may accelerate the movliaent of said valve instead or' retarding the same.

By reversing the connections carrying,Y the fluid pressure to and away from the thermostat, the pipe G becoming' the supply pipe and pipe :t the pipe carrying fluid to the motor and having in it the restricted openhun` the action of the valve will become positive and the actionof -the motor will be accelerated instead of being, retarded.

YHaving thus described my invention, what l claim as new and desire to secure by Letters Patent, is:

l. The combination with a source of fluid pressure, of a motor actuated thereby, a valve controlling; the pressure to'which the motor is subjected, a balancing and energy storing device associated with and tending; to close said valve and adjusted to balance the effective fluid pressure to which the Valve is subjected, and a` thermostatic element 'for Varying the energy stored in said storage device to thereby vary, in response to teinperature changes, the fluid pressure to which thermotor issubjected.l A

2. The combination with a'spurce of fluid pressure, of a motor actuated thereby. a valve controlling the pressure to which the motor is subjected and arranged so that the valve is acted'upon by the effective fluid pressure, a balancing and energy storage device associated with and tending to close said valve-and adjusted to balance the effects ivc fluid pressure to which the Valve 4is sub jec ed, and a theiuiostatic element 'for vary ingthe energy stored vin said storage devis; to thereby vary, in response to teniperature changes. the fluid pressure to which. the motor is subjected.

The combination with a source of' duid supply, of a motor supplied with fluid thereby, a valve for varying the fluid pressure to which 'the motor is subjected, an ener gl. storage device tendine' to close said valve and adjusted to be balanced against the effective fluid pressure exerted upon said valve. and a thermostat for farying the energy stored in said storage device to thereby vary.- in response to temperature changes. the fluid pressure to which the motor is subjected.

at. The combination with a. source of fluid supply. of an inelosed valve controlling the passage ot the fluid fromsaid source. the iuelosure having a vent leading therefrom` a motor eoininunicatingr with said inclosi'ire, a storage vspring inelosed with said 'alve and adjusted to be balanced against the effective fluid pressure exerted upon said valve. and a thermostat for varying' the energy stored in said spring to thereby vary. iu response to temperature changes. the fluid pressure to which the motor is subjected.y

/\`:"n.The combination with a thermostat having a chamber. therein. of a ,source of fluid supply connected with said chamber. a valve adapted to controlqthemflonkof sireh fluid to the chamber. said-\chambcr liaviirgss`M a vent leading therefrom, a-, motor.operated by the fluid from said sourcof fluid supply;

pcrature changes. the fluid pressure to which the motor is subjected. 1

6. The combination with a thermostat having a chamber therein. of a source of Afluid supply connected with said chamber,

a valve controllingr the variations of pressure from said source within the chamber. said chamber having a ventleading therefrom, a motor operated by the fluid from said source of fluid supply. and a sto age spring within the chamber associated with said valve and adjusted to be balanced against the. effective fluid pressure exerted upon said valve. said thermostat serving to vary the energy stored in said spring to thereby vary. iinresponse to tempe lature. changes. the fluid pressure to which the motor is subjected.

A 7. The combination with means for ronvevirgr a fluid, of a` valve roi/ennuier the flow of. said fluid. an energy-storing spring associated with and tending to close said valve and adjusted to be balanced against the izo ' ing e vent, means e'ective iiudpressure exerted on said valve, und :t thermostat `tor varying the energy stored, in seid springf y S. combination `with means -for conveying it luid, oan valve governing the ilow oi: seid lluid and being under' the iniuence oit the unid pressure on bothV sides thereof,

un energy-storing spring associated with and 'tending to close seid'velve und adjusted to be balanced Jigsinst the effective' fluid pressure exerted on seid: velve,l'and ethermostet 'for varying the energy stored in 'said sprinO. l

9. The combination with s source or supv ply of iluid under pressure, of e motor lievior conducting fluidv from seid source of supply to saidmo'tor and cornprising u chamber, e port through which the fluid passes to seid chamber, e valve forv ually varying the power applied by seid lastnzuned means to said valve.

ll. The. combination of a source ol supply of fluid under pressure, e motor having e vent, means for controlling tn'e flow of fluid from seid source of supply to seid motor, .said means comprising e chamber' in communication With seid source of supply and said motor, a vulve in seid chamber subjected to the supply pressure on one side and to tbe motor pressure on the opposite side, elastic means tending to close Seid valve against the supply pressure 'to cut od the iiow of fluid from s id source oi supply, and thermostatieully controlled means for varying the force applied Seil last-nemed means.

l2. The combination of s source of supply oie duid under pressure, e'moter vented to tbe atmosphere, means for conducting luid from sand source oi' supply to said motor, e vulve located in the path of movement of the lluid and surrounded by seid iiluid, seid vulve being arranged to close :eg-einst the direction of movement of the fluid, elastic means tendingto close seid valve, andl thermostaticellyectuuted means for varying the force applied by seid lestnamed means.` V

13. The combination of e vented motor, e source of fluid supply and means for controlling the flow offluid" to said motor, said means havinge chamber in'communieation`k with said motor and a valve in said chamber for governing the flow' of fluid to said chumber, said valve being subjected to both the supply pressure and the pressure Within seid chamber, a thermostatic element arranged to 'close said valve, and e power "storage device interposed between said thermostatic element and said valve.

1.4. The combination of e' vented motor, a source of duid supply, end means for control- '.ling tlie ilowof fluid to said motor, seid meansheving e chamber in communication with said motor and a valve in seid chamber for governing the flow of fluid to said cliember,ssid valve being subjected to both the supply pressure and the pressure Within seid chamber, a thermostatic element adapted to close seid valve, and a spring interposed between seid elementend said valve.

15. The combination of a vented motor, e source of iiuid supply and means'for controlling the How of fluid to said motor, seid means having e chamber in communication with said motor and eyalve in said chamber for governing the ioyv' of fluid to'said chember, Suid valve being subjected to. the pressure Within said chamber, a thermostetic element arranged to control said valve, and e yield@ ing element interposed between said thermostatic element and said valve.

16. The combination with e source of supply of fluid underv pressure, of e motor, means for conducting fluid from seid source of supply to said motoryeud means for controlling the iow oflfluid to said motor comprising e valve arranged toclose in a direction opposite the direction of movement of4 the fluid, a spring for vclosing seid valve,

and thermosteticelly controlled means for varying the strength osaid sprintf.

In Witness whereof, I have hereunto subscribed my name in the presence of two Wit- EDWARD', vv. coureur Witnesses:

F. E.l NEWTON, E. EDMoNe'roN, Jr. 

